In
geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
, a stock is an
igneous intrusion that has a surface exposure of less than ,
[Whittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984, p. 513. .] differing from
batholiths only in being smaller. A stock has a
discordant relationship with the rocks that it intrudes. Many stocks are
cupolas of hidden batholiths.
Some circular or elliptical stocks may be
volcanic plugs, which fill the vents of now extinct volcanoes.
A boss is a small stock.
Examples
* the Alta and Clayton Peak stocks (composed of
granodiorite), near
Park City, Utah
* the Hellroaring Creek and
Salal Creek stocks (of
granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...
-granodiorite and
quartz monzonite, respectively) in
British Columbia
British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...
, Canada
* the Céret stock (of
gabbro and
diorite
Diorite ( ) is an intrusive rock, intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is Intermediate composition, inter ...
) in
Pyrénées-Orientales
Pyrénées-Orientales (; ; ; ), also known as Northern Catalonia, is a departments of France, department of the Regions of France, region of Occitania (administrative region), Occitania, Southern France, adjacent to the northern Spain, Spanish ...
, France
* the Parashi stock (of
tonalite) in
La Guajira Department, Colombia
* stocks of
syenite in the Caldera de Tejeda on
Gran Canaria
*
Ailsa Craig granitic boss, which forms a volcanic plug, in Scotland
References
Igneous intrusions
{{igneous-petrology-stub